Method of making hollow glass articles.



:No. 688,923. Patented Dec. I7, I96". G. W. BLAIR &. H. J. HAYS. METHOD OF MAKING HOLLOW GLASS ARTICLES.

(Application filed Nov. 19, 1897.) (N 0 M 0 d e l WITNESSES: INVENTORS. {77M 3 UNITED STATES PATENT OFFICE.

GEORGE W'. BLAIR, OF PITTSBURG, AND HARRY J; H-AYS, OF lALl'JlVIN TOWNSHIP, PENNSYLVANIA.

SPECIFICATION forming part of Letters Patent'No. 688,923, dated December 17, 1901.

I Application filed November 19,1897. Serial No. 669,091. (No model.)

To ctZZ whom it may concern:

Be it known that we, GEORGE W. BLAIR, of Pittsburg, and HARRY J. HAYS, of Baldwin township, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Methods of Making Hollow Glass Articles, of which the following is a full, clear, and exact description, reference, being had to the accompanying drawings, forming part of this specification, in which' Figure 1 is a partial side elevatiompartly 'in section, showing one form of apparatus for carrying out our invention. Fig. 2 is a sectional view of a modified form of blank and the mold used in its manufacture, and Fig. 3 is a sectional view of a modified form of blank.

Our invention relates to the manufacture of hollowarticles of glassware; and it is designed to greatly eheapen and improve the manufacture of such articles.

To this end it consists in forming a hollow blank and then elongating the blank by drawing on or approximately on the lines of its outer circumference.

ends of the blank shouldbe on parallel lines, I whereby anypossible tendency toward the collapsing of the cylinder is prevented. To this end we may secure the blank to a stretcher at points at or near the lines of its outer circumfere'nce, or we form a blank having one end of glass that is relatively thinner than the sides of-the blank, which end is preferably closed by the thin glass, so that the end will harden and stiflfen, while the sides, having the greater quantity of glass, remain soft and plastic and while the end is so hardened and the sides soft elongate the blank to the desired size and shape, the stiflened end of the blank keeping the lines of force extended throughout to the outer circumference of the blank.

mold is the sectional mold-ring 4, the parts ofwhich are hinged to a lug 5, projecting from a ring 6, secured to the standard 3. Theother ring7 of the mold is hinged upon a cross piece or head on the end of the supporting-rod 8, which also carries the base-piece 9 of the mold. This end ring is provided on its interior circumference-with an annular projection 10, forming an annular recess 11 directly above the base-piece 9. The rod 8 moves within a guide 12 in asuitabletable 13 and is supported and moved by a pin l4,which extends through slots in the guide and at its ends is pivotally connected bylinks 15 with leversldwhich are secured at their outer ends to a shaft 17. The shaft 17 is carried in suitable bearings in a bracket 18, which is secured to the support 3, and is rotated by a handle 19. The table 13 may be carried on the support 3 by means of- 1 provided with a recess 21 on its inner circumference, in which a projecting ring is formed vupon the glass blank when the blank is pressed. lhe plunger 22 of the mold is fitted on a press in the usual manner, so. as to reciprocate within the mold, and is suihciently tapered to withdraw easily from the mold after the glass is pressed. This plunger is of such shape that when it has entered the mold there is left, preferably, a smaller space-between the plunger and the base-piece 9 than between the plunger and the sides of the mold.

The operation is as follows: The parts'of the mold being in the position shown in the drawings and the plunger being raised, a suitable quantity of molten glass is dropped into the mold-cavity. The plunger 22' is then depressed, and the glass is forced into all parts of the mold-cavity, thus securing one end of the blank to one end mold-ring in the recess 21 and the other end of the blank to the other mold-ring in the recess 11, the closed end of the blank being composed of glass relatively thinner than the sides of the blank, which thin portion of glass quickly hardens and stiff- -ens against the base-piece t). The plunger ring-f4 by the rod 8, wherebythe blank may be elongated into a cylinder, (indicated by the dotted lines in Fig. 1,) which cylinderis readily released. from the two (and rings of the mold"-and is suitable for cracking and fOIlIling into window-glass. Instead of thus drawingont the glass blank in the form of a cylinder it may be madeinto articles of other -form-such as molded lamp-chimneys, globes,

&c.--by inclosing the blank during or after the stretching operation in the moldhaving a matrix of the desired form and expanding and elongating the blank within such matrix.

In the operation just described'it is advisable to use air-blowing in connection with the. pressing or drawing of the cylinder, whereby 'suflicient air is supplied lU-llie interior of the cylinder as itis drawn to insure the prevention of bending or collapsing of the glass, and tothis end the plunger may be provided with an air-orifice and a channel for the passage of air to the interior of the blank. \Ve prefer, however, in such case to employ the modified form of p-lungerand mold shownin Fig. 2, in which the base .i is movable and is reciproeated bythe-handle'23and the pin 2%, which moves in a slot in a post 25. The plunger 22 is hollow and is provided with an air-valve 26. Suitable air connections are made with the hollow plunger. ,Molten glass having been placed in the cavity-of the tnold, the base 9 beihg in its closed position, the plunger is caused to enter the mold and/press the blank in the manner; already described. The base 9 is then moved suificiently to expose the recess ll. The plunger is retracted somewhat, so as to free the glass, and air is caused 'to pass through the; valve 26, which blows the glass forming'the closed end of the blank into the recess 11 and against the base 9,

thereby thinning and chilling the glass and forming a blow-over in' the recess'll, thataffords a secure attachment of the end of the blank to. the rod 8 and one that is easily crackedoif when the cylinderis formed.- The air may be continued to be supplied during the formation of the cylinder. In, Fig. 3 we show another form of blank, in which the attachment of the blank to the base 9 is caused by the pressingot a button 27 in arecess-in the base. attachment to tile drawing-rod 8 is on a vertical line with the center ofthe cylinder yet In thismase although the point of -owing to the chilling ofthe portion of glass closing the end of the cylinder the drawing force is exerted on substantially the lines of the circumference of the blank. V-Vhere the grip is formed by pressing a lip or when other means of efiTecting a grip around the periphcry. of the lower end of the blank is employed, the described thinness of the glass at the lower end becomes unessential, though its use may be advantageous. The use of such a thin portion at the lower end is essential only when it is desired that a pulling forceapplied at or near the center of a blank like that of Fig. '3 shall be transmitted to the periphery of the lower end of the blank, so as to be practically operative as a pulling force substantially in the vertical annular plane of the blank.

f The advantages of ourinvention will be ap-' parent to those skilled in the art, since in the operation of forming hollow glass articles (whether such articles be afterward changed in form-as, for instance, by cracking and flattening into a sheet-or be in final form, as

where a mold having a mold-cavityin the form of a finished article is placed about the blank and the blank expanded therein) uniformity in the drawing of the blank is-insured and rapidity andcertainty of operation are obtained. v

Although we have described the use of apparatus of improved construction for the practice of our method, we do. not desire to limit ourselves thereto,as a great variety of means may be employed for such purpose.

We claim- -1. The method of forming hollow glass articles, which consists in forming a hollow blank and while at least a portion of the sides of the blank is out of contact laterally' with the matrix in-which it was formed and a portion of theblank is still held thereby, elongating the blank by drawing or pulling the same solely on the lines of it's circumference.

2. The method of forming hollow glass articles, which consists in forming a hollow blank and while at least a portion of the sides of the blank is out of lateral contact with the matrix in which it was formed and a portion of the blank is'still held thereby, elongating the blank by drawing or pulling the same solely on the lines of its circumference; and forcing air into the interior of theblank during such drawing or pulling.

too.

In testimony whereof wehave hereunto set 

